From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, linux-coco@lists.linux.dev,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/coco, x86/sev: Use cpu_feature_enabled() to detect SEV guest flavor
Date: Tue, 5 Dec 2023 18:00:12 +0300 [thread overview]
Message-ID: <20231205150012.6lma2wzcellr7pz7@box.shutemov.name> (raw)
In-Reply-To: <20231205144619.GCZW83uzAomKmupn7j@fat_crate.local>
On Tue, Dec 05, 2023 at 03:46:19PM +0100, Borislav Petkov wrote:
> On Tue, Dec 05, 2023 at 05:37:38PM +0300, Kirill A. Shutemov wrote:
> > The SEV code uses cc_platform_has() checks to detect the SEV flavor.
> > However, these checks can sometimes produce false positives depending on
> > the context.
> >
> > For example, sev_map_percpu_data() uses CC_ATTR_GUEST_MEM_ENCRYPT to
> > detect SEV guest, but this check will also pass for TDX guests.
>
> Well, a function prefixed with "sev_" should check cc_vendor first...
I don't think cc_platform_has() is the right check. On TDX side we use
X86_FEATURE_TDX_GUEST for this and it works better than stretching
CC_ATTRs beyond their meaning.
--
Kiryl Shutsemau / Kirill A. Shutemov
next prev parent reply other threads:[~2023-12-05 15:00 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-05 14:37 [PATCH] x86/coco, x86/sev: Use cpu_feature_enabled() to detect SEV guest flavor Kirill A. Shutemov
2023-12-05 14:46 ` Borislav Petkov
2023-12-05 15:00 ` Kirill A. Shutemov [this message]
2023-12-05 15:06 ` Borislav Petkov
2023-12-05 15:14 ` Kirill A. Shutemov
2023-12-05 16:00 ` Borislav Petkov
2023-12-05 17:16 ` Kirill A. Shutemov
2023-12-05 17:24 ` Borislav Petkov
2023-12-05 18:08 ` Kirill A. Shutemov
2023-12-05 18:52 ` Borislav Petkov
2023-12-05 20:33 ` Borislav Petkov
2024-01-02 12:22 ` Kirill A. Shutemov
2024-01-02 12:30 ` Borislav Petkov
2023-12-05 17:27 ` Jeremi Piotrowski
2023-12-05 17:12 ` kernel test robot
2023-12-05 19:24 ` kernel test robot
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